The present invention relates generally to evaporator tools, bell jar systems and processes and more particularly to methods and apparatus for vapor depositing layers of vaporized material on a substrate and still more specifically to methods and techniques for vapor depositing layers of vaporized material on a substrate at different angles and orientation in a vacuum.
One of the most reliable methods of aligning liquid crystal molecules for the formation of liquid crystal light valves and display panels is by the evaporation of dielectric materials such as SiO.sub.x, SiO.sub.2, etc. onto a substrate surface at various slant angles. The slant angles of the liquid crystal molecules that are deposited on the substrate, however, depend upon the evaporation angles. The conventional method to achieve variation in evaporation angles is to place the substrate which is to receive the vapor deposited layers in a vacuum bell jar of an evaporator fixture with the substrate disposed at a predetermined angle with respect to the evaporating material. The next step is to vapor deposit a film of material such as SiO.sub.2 onto the substrate. The evaporator fixture is then opened and the substrate is rotated and placed at a different angle. Another layer of material is then vapor deposited on the substrate.
While the evaporator fixture is open and the substrate is reoriented it can and does get contaminated. This requirement to reopen the evaporator fixture to reorient the substrate and the subsequent substrate contamination which results is not only an unnecessarily time consuming process but also considerably lowers the product yield.